Hi everybody,

Here is a very simple question :
I have two strictly positive reals r and s and the expression
a := r^2 – r*s + s^2
Obviously a is strictly positive too

But I’m not capable to prove this with Maple (2016, Windows 7), even after having declared r and s both positive which, I thought, would have prevent Maple to consider them as potentially complex.
I failed in using "is", "coulditbe", "use RealDomain ..." and so on

Totally distressed I tried to do something simpler ... which ultimately appeared still more upsetting

restart:
assume(r, ‘positive’):
coulditbe(r, ‘complex’) ;    # the answer is (surprising ?) true

I'm probably doing some mistake bigger than I but I don't find it !

Could you be compassionate enough to enlight me !!!

Mammoth thanks in advance

Hi,

This question concerns the package GraphTheory
( Maple 2015 on a Windows 7 PC )

Let G1 be some graph and V a list of vertices in G1
The default colors DrawGraph uses for the vertices is yellow

I define the graph G2 this way :
    G2 := copy(G1):
    HighlightVertex(G2, V, red);
    DrawGraph(G2);
Obviously the result is a graph where vertices in V are red while the remaining ones are still yellow

Question 1 :  Why does the command DrawGraph(G1) returns exactly the same picture ?
I have thought that defining G2 as a copy of G1 would have preserved the default colouring of the vertices.
Note that the same undesired (at least for me) thing occurs with the  HighlightEdges command.

Question 2 : Is it possible to retrieve the original colouring of G1 without using HighlightVertex(G1, V, yellow)  ?

Thank you in advance

Morning all,

I repeatedly solve (command solve) a collection of systems of inequalies. Some of them can have no solution, but I am able to check if a solution has been found or not, and then take some decision about the system in question.

I have placed a few print commands at different critical locations within the loop where those systems are constructed and possibly solved.
Every time solve fails finding a solution it returns me a "no solution found" warning.
In order to keep my printings readable, could it be possible to avoid those warnings ?
Is there some "try & catch" like mechanism to manage warnings ?

Thank you all in advance

Hi everybody, 

Neither of these questions is vital but answers will be greatly appreciated

-------------------------------------------------------------------------------------------------
Question 1 :
Is it possible to manage programatically the character fonts in a printf command ?
(for instance to print some piece of text in bold font ... without selecting it and clicking the bold B of the toolbar)

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Question 2 :

In order to have a nice render, I use to create my own format for printf command. For instance, when I have to “printf” some text I usually compute its length L and my “printf” format constructor contains a command  like  MyFormat := cat(“%”, L, “a”)

Unfortunately the length(…) command seems to be sensitive to accented characters :
                                     For people not familiar with french, "dégénéré"  (note the acute accents) means "degenerate".
length(“dégénéré”) returns 12
length(“degenere”) returns 8
… which of course leads to a very inelegant render, which is all I wanted to avoid

Why does “length” behave this way ?
Is it possible to bypass this annoyance while ensuring “dégénéré” has length 8 ?


Thanks in advance

Hi everybody, 

Only weights of type "numeric" can be used in a weighted graph (package GraphTheory) .
Is it possible to bypass this limitation and affect an infinite weight to an edge ?
If not possible, does it exist some "highest numeric value" in Maple I could use instead ?
(the trick of a very high value doesn't suit me)

Subsidiary question : is it possible to change the printing format for those weights ?
For instance   GraphTheory:-SetEdgeWeight(MyGraph, MyEdge, 123.4) plots the value 123 on edfe MyEdge

Thanks in advance